<p>Even better is <a href="https://developers.facebook.com/docs/graph-api/reference/user">https://developers.facebook.com/docs/graph-api/reference/user</a> which is official documentation. The email field is described as:</p>

<blockquote>
<p>The person's primary email address listed on their profile. This field will not be returned if no valid email address is available</p>
</blockquote>

<p style="font-size:small;-webkit-text-size-adjust:none;color:#666;">—<br>Reply to this email directly or <a href="https://github.com/openstreetmap/openstreetmap-website/pull/1096#issuecomment-160681434">view it on GitHub</a>.<img alt="" height="1" src="https://github.com/notifications/beacon/ABWnLT_uh1mX9ruphmpU7yRrLQg0yP1aks5pLHJCgaJpZM4GrPC4.gif" width="1" /></p>
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